diff --git a/Nef_S2/doc_tex/Nef_S2/PkgDescription.tex b/Nef_S2/doc_tex/Nef_S2/PkgDescription.tex
index cc5968f6238..ee4981f3cd9 100644
--- a/Nef_S2/doc_tex/Nef_S2/PkgDescription.tex
+++ b/Nef_S2/doc_tex/Nef_S2/PkgDescription.tex
@@ -1,5 +1,6 @@
 
 \begin{ccPkgDescription}{2D Boolean Operations on Nef Polygons Embedded on the Sphere \label{Pkg:NefS2}}
+\ccHowToCite{cgal:s-bonpes2-06}
 \ccPkgSummary{This package offers the equivalent to 2D Nef Polygons in the plane. 
 Here halfplanes correspond to half spheres delimited by great circles. }